1) a past history of ocular inflammatory diseases, ocular surgery, or traumatic diseases less than 3 months before entry, 2) use of other topical eye drops or systemic ocular hypertensive drugs, 3) patients who wear contact lenses, or 4) under 20 years old during the study. Moreover, patients at risk of visual field progression or visual acuity worsening during the study were excluded according to the judgement of physicians in charge.